1. Field of the Invention
The present invention pertains to low voltage, high speed nano-vacuum electronic devices, and, in particular, the device structure wherein Coulombic repulsion in a two-dimensional electron system induced in a cathode of the electronic device is used to enable thresholdless emission of electrons and their subsequent ballistic transport in ambient air.
2. Description of the Related Art
A common requirement in developing high speed electronic devices is to reduce the carrier transport time, and this is usually achieved by decreasing the channel length and/or by increasing the carrier velocity to a ballistic regime. Achieving a ballistic transport of charge carriers in a solid-state medium, however, requires a careful design of materials and structure, because a high electric field applied across a channel often incurs numerous conflicting situations with a requisite scattering-free transport in the medium. Vacuum would serve as an ideal medium for ballistic transport of electrons, but vacuum electronic devices commonly suffer from low emission current and high operating voltage.
Thus, there is a need for an electronic device that offers an ultrafast and high current density operation at low voltage in room-temperature ambient air.